Right now I have stock suspension so obviously I have enough flex that both wheels stay on the ground. Anyone know how stiff the BMW performance suspension is? Will I be ok with a Quaife? Is Maintenance the only downside to Wavetrac over Quaife?

There is no maintenance with a Wavetrac, so makes no difference compared to a Quaife fitment apart from not loosing traction if one wheel comes off the ground.

It's not the stiffness of the suspension rather than stiff anti-roll bars that reduce suspension droop. The BMW performance suspension will have the same droop as the standard M-sport setup so you'd be fine with the Quaife.

My VAC trip is still TBD, awaiting some of the parts from Europe. Longest lead time item is the springs; it seems the US distributor changed abruptly so they are at least three weeks out. Am thinking about doing everything but the springs and dampers first, so that could be in the next week or so possibly.

Yes, very annoying. Would have been nice if they proactively told us about the switch!!

Quote:

Originally Posted by 335dFan

My VAC trip is still TBD, awaiting some of the parts from Europe. Longest lead time item is the springs; it seems the US distributor changed abruptly so they are at least three weeks out. Am thinking about doing everything but the springs and dampers first, so that could be in the next week or so possibly.

It depends what you’re doing with the car. If it’s hardcore trackwork the OS Giken is far superior due to the high percentage lock-up available (ie better traction) and adjustability to let you change maximum lock-up and pre-load.

OS Giken is mainly used in FWD cars in Japan. Take a look at their website. Lock up is ok for FWD cars, but for RWD cars, you don't want lock up while you are in mid corner.

See 3:30 to 3:50

Quote:

Originally Posted by Techevo

A Quaife isn’t a 1 way, 1.5 way or 2 way diff. This classification isn’t used for a non locking torsen (TORque SENsing) helical diff. The Quaife still transfers torque under deceleration.

The OS Superlock will be available in 1, 1.5 or 2 way. 1.5 way is exactly what you want for a RWD track/race car. This means it has maximum lock-up on acceleration (% lock-up depending on plate config, ramp angle and oil used) and a smaller percentage lock-up on deceleration (off throttle and braking) This slight lock-up on decel helps keep the rear end stable. It is not ‘open’ when you let off the throttle!

A 2 way diff isn’t called as such because it works under zero load (nothing to do with it) it is because it has the same percentage lock-up under acceleration and deceleration, and only really to be fitted to a ‘drift’ car due to the oversteer characteristics it causes.

I stand partially corrected, as should you. For a 1, 1.5, or 2 way diff, the issue is behavior on Load, No load, and overrun situations. I confused overrun with zero, or no load. on overrun, such as suddenly lifting off throttle during corner entry a 1.5 way does have more limiting torque, but when you power out of the corner the 2 way has more limiting torque. As much limiting torque in reverse as it does in the forward direction. % lock up has nothing to do with this.

Quote:

Originally Posted by Techevo

Functionally, the full plated OS diff is the most efficient differential due to being able to create the highest percentage lock-up of all types.

Basically these are some guidelines for using the different diffs.

For a mainly road car, with occasional trackwork where the suspension droop is adequate to not cause a lifted wheel, the Quaife diff is preferable.

If there is any possibility of lifting a wheel a Wavetrac is preferential.

For maximum traction and lock-up and much better adjustability, but will require more maintenance and not fit and forget, the full plated diff such as the OS, is preferable.

Functionally the OS is the most complicated. % lock up has to be determined and set up before manufacture. In units where % lock up is adjustable post manufacturing, the process of changing lock up percentage is too complicated, and time consuming. Then again, there is the issue of lock up being undesirable in RWD cars, during cornering.

I think Quaife is oft mentioned because they are so bullet proof and unmatched when it comes to reliability. Some people have said Wavetrac has had clunking issues which others have attributed to poor installs. Essentially, Wavetrac and OS haven't been around as long so people point to the Quaife first and recommend that.

Quaife is a 1 way diff. Read my earlier explanation. It will only work when you are accelerating out of a corner, and the slipping wheel has at least some traction. In all other conditions, it acts like an open diff.

Quaife is a 1 way diff. Read my earlier explanation. It will only work when you are accelerating out of a corner, and the slipping wheel has at least some traction. In all other conditions, it acts like an open diff.

Thanks killer. Im getting to understand the tech a bit from your post, but not necessarily the differences in application, although corner accel was the big reason i want one!

OS Giken is mainly used in FWD cars in Japan. Take a look at their website. Lock up is ok for FWD cars, but for RWD cars, you don't want lock up while you are in mid corner.

I donít need to look at a video or website to understand how a plated differential works.

I strip, setup and rebuild plated diffs every week, for all sorts of cars and applications, tailoring ramp angle, preload and plate configuration depending on car and application.

OS Giken, Cusco, Kazz etc, it doesnít matter, they all work with the same principle and are used in front wheel drive, 4 wheel drive and rear wheel drive for the same reason, obtaining maximum traction and characteristics dependant on setup.

I really donít think you fully understand how they work and what they do, if you make a statement ĎLock up is ok for FWD cars, but for RWD cars, you don't want lock up while you are in mid cornerí

With a 1.5 way differential (which is what you want for a normal track/racecar) when accelerating through a corner you want and need maximum lock-up for the best traction available. Maximum lock-up doesnít mean 100% lock-up, it means the maximum available depending on ramp angle, plate number and configuration. This is setup by the installer depending on application and driver preference. Mid-corner on trailing throttle, you will not have lock-up, unless preload is very high, and for a tarmac car this should be set to a low figure. Basically you want lock-up under acceleration and a small amount of lock-up under decal to help stabilise the rear end.

I think you are confusing a 4WD off road vehicle which has 'locking diffs' which gives you 100% lock-up across the axle. A plated LSD such as the OS, does not give 100% lock-up!! You could have 40% lock-up if configured in a certain way.

Quote:

Originally Posted by Killerfish2012

I stand partially corrected, as should you. For a 1, 1.5, or 2 way diff, the issue is behavior on Load, No load, and overrun situations. I confused overrun with zero, or no load. on overrun, such as suddenly lifting off throttle during corner entry a 1.5 way does have more limiting torque, but when you power out of the corner the 2 way has more limiting torque. As much limiting torque in reverse as it does in the forward direction. % lock up has nothing to do with this.

What are you talking about??

Lock-up has everything to do with it, that is exactly how a plated LSD works.

Friction discs and plates are pressed together (locking them together) which basically transfers torque away from the spinning wheel to the wheel with more traction. Itís a totally mechanical process, very simple in design and application and physically locks the left and right wheels together, up to a maximum percentage lock-up depending on the amount of alternating plates (ie total friction surface area) and ramp angle (effective leverage pressing the plates together)

A 1.5 way is designated as such because it has maximum lock-up under acceleration, depending on ramp angle, number of plates and plate configuration, i.e. 65% and partial lock-up on decel i.e. 20%

A 2 way will have exactly the same maximum lock-up under accel as a 1.5 way if the set-up is the same, i.e. 65%, but will also then have 65% lock-up on decel.

Quote:

Originally Posted by Killerfish2012

Functionally the OS is the most complicated. % lock up has to be determined and set up before manufacture. In units where % lock up is adjustable post manufacturing, the process of changing lock up percentage is too complicated, and time consuming. Then again, there is the issue of lock up being undesirable in RWD cars, during cornering

Changing a plated diffís maximum lock-up is very easy to do, itís not complicated, it is time consuming though, but once setup in the sweet spot, the benefits of improved traction out way a helical diff. The problem is, 99.9% of people donít know how to set them up for maximum performance depending on driver preference. All plated LSDís can be adjusted in regards to maximum lock-up by adjusting plate configuration.

If lock-up was undesirable in a RWD car, as you have mentioned twice now, then running an open diff would be faster!!

With a 1.5 way differential (which is what you want for a normal track/racecar) when accelerating through a corner you want and need maximum lock-up for the best traction available. Maximum lock-up doesn’t mean 100% lock-up, it means the maximum available depending on ramp angle, plate number and configuration. This is setup by the installer depending on application and driver preference. Mid-corner on trailing throttle, you will not have lock-up, unless preload is very high, and for a tarmac car this should be set to a low figure. Basically you want lock-up under acceleration and a small amount of lock-up under decal to help stabilise the rear end.

Therein lies the problem. Folks in the US like to go to different tracks, which have widely varying configurations. We can't simply just decide on what %lock is ideal for the 335I. Maybe OS giken has determined that 40% lock up is fine for most cornering situations (which they don't, cuz they rely on you the customer to decide the percentage when you order it). Further complicating this issue is the fact that people like to change their suspension set up in the rear. M3 subframe bushings, stiffer/adjustable non oem rear track struts, staggered wheel and tire setups etc. Because of these two reasons, varying cornering steepness, and modifications to the suspension, I find it extremely hard to believe in a one size fits all lock up %.

Quote:

Originally Posted by Techevo

Changing a plated diff’s maximum lock-up is very easy to do, it’s not complicated, it is time consuming though, but once setup in the sweet spot, the benefits of improved traction out way a helical diff. The problem is, 99.9% of people don’t know how to set them up for maximum performance depending on driver preference. All plated LSD’s can be adjusted in regards to maximum lock-up by adjusting plate configuration.

You've just shot yourself in the foot there mate, by loosing the argument on practicality. Most folks on here are among those 99.9%, and don't know how to start taking apart their LSD, trying to find the "sweet spot" come track day. Wavetrac wins here hands down.

OS Giken for the extremely mechanically inclined enthusiasts who enjoy taking their cars apart, come track day. Another membership criteria, for this same crowd is that they should never take their car off road, even by accident, cuz if one rear tire is lifted off the ground, their LSD won't be able to get their car moving again.

Therein lies the problem. Folks in the US like to go to different tracks, which have widely varying configurations. We can't simply just decide on what %lock is ideal for the 335I. Maybe OS giken has determined that 40% lock up is fine for most cornering situations (which they don't, cuz they rely on you the customer to decide the percentage when you order it). Further complicating this issue is the fact that people like to change their suspension set up in the rear. M3 subframe bushings, stiffer/adjustable non oem rear track struts, staggered wheel and tire setups etc. Because of these two reasons, varying cornering steepness, and modifications to the suspension, I find it extremely hard to believe in a one size fits all lock up %.

Your posts continue to show you really donít understand the subject, so why are you posting?

You donít need to set the diff up for different tracks, you just need to fit the diff as it comes, which has been setup for that model in mind, then tweak once fitted if youíre not happy. It is setup for the car, not for a certain track.

If youíre going to change many other aspects of the car for maximum performance, then youíll make the effort and setup the diff aswell, or find someone that can. (like Mike @VAC)

This discussion is which one is best, or what benefits one has over the other for the cost, not about practicality, and not once has the OP mentioned it.

Quote:

Originally Posted by Killerfish2012

You've just shot yourself in the foot there mate, by loosing the argument on practicality. Most folks on here are among those 99.9%, and don't know how to start taking apart their LSD, trying to find the "sweet spot" come track day. Wavetrac wins here hands down.

Iím not arguing, Iím posting facts from 20+ years of hands on experience.

Iíve never once mentioned practicality, please show where I have??

I haven't said the Wavetrac is less practical, you seem to be trying to argue a point that hasn't been written, very strange.

Actually, I wrote ĎOS Giken for hardcore street/track (best traction/adjustablility)í

The OP asked why the OS are better, Iíve answered with facts. If you want best performance, youíll find someone like me who understands exactly how they work and how to set them up, and get them to set it up for you.

As Mike@VAC wrote - ĎWe suggest 99.99% of the time that you run it as delivered. Street, circuit, hill climb, drift all use the Super Locks with ultimate success.

I also strongly suggest the Super Lock - TCD is generally not necessary (unless you want the best of the best). You cannot hear a super lock - we have one in our shop 135i and its no different (sounding) than the Quaife or Wavetrac that we had in it beforeí

Quote:

Originally Posted by Killerfish2012

Another membership criteria, for this same crowd is that they should never take their car off road, even by accident, cuz if one rear tire is lifted off the ground, their LSD won't be able to get their car moving again.

So you think a plated LSD wonít work with one wheel off the ground? We seem to be going round in circles here.

Your posts continue to show you really don’t understand the subject, so why are you posting?

Because I enjoy making you continue to concede defeat.

Quote:

Originally Posted by Techevo

You don’t need to set the diff up for different tracks, you just need to fit the diff as it comes, which has been setup for that model in mind, then tweak once fitted if you’re not happy. It is setup for the car, not for a certain track.

NO, it is not set up with the model in mind. Go to the OS giken website, which you refuse to visit, and check the facts. When you order the OS giken diff, you have to tell them what % lock up you would like. This is the same in the adjustable, and non adjustable diffs. With the adjustable ones, being the only user end modifiable unit.

Quote:

Originally Posted by Techevo

This discussion is which one is best, or what benefits one has over the other for the cost, not about practicality, and not once has the OP mentioned it

We can take practicality out of the discussion if it's making you sweat. but as far as cost goes, you haven't explained what the major difference is between the Super Lock unit of OS Giken (the only one which we can even compare to wavetrac), and wavetrac, to justify the Large Price difference. I can't pay for the difference between a 1.5 way and 2 way diff because the difference is probably not even noticeable to 99% of the drivers that track their car.

Quote:

Originally Posted by Techevo

I’m not arguing, I’m posting facts from 20+ years of hands on experience.

No one is challenging your alleged experience, but exactly how many years have you spent driving at the track. I know I'm more experienced than you.

Quote:

Originally Posted by Techevo

I’ve never once mentioned practicality, please show where I have?? I haven't said the Wavetrac is less practical, you seem to be trying to argue a point that hasn't been written, very strange.

No, the OS giken is FAR less practical for anyone other than a professional race team to own. read what I wrote with care.

Quote:

Originally Posted by Techevo

Actually, I wrote ‘OS Giken for hardcore street/track (best traction/adjustablility) The OP asked why the OS are better, I’ve answered with facts. If you want best performance, you’ll find someone like me who understands exactly how they work and how to set them up, and get them to set it up for you.

That's your opinion backed with claims of years of dealing with clutch style diffs, not experience behind the wheel, at a track, once the installs were complete.

Quote:

Originally Posted by Techevo

Rubbish.

Garbage (US)

Quote:

Originally Posted by Techevo

So you think a plated LSD won’t work with one wheel off the ground? We seem to be going round in circles here. :

It will "work", but it won't move the vehicle, appreciably. We've seen videos of a vehicle with wavetrac fitted, and it moves the vehicle. Show us filmed evidence of the Superlock moving the vehicle

Lastly, here is video of a 335I at the track with the wavetrac fitted. Please tell me exactly how a superlock will improve his corner entry, exit, or any other aspect of his driving:

NO, it is not set up with the model in mind. Go to the OS giken website, which you refuse to visit, and check the facts. When you order the OS giken diff, you have to tell them what % lock up you would like. This is the same in the adjustable, and non adjustable diffs. With the adjustable ones, being the only user end modifiable unit.

Your answers get more and more ridiculous and you make complete assumptions without facts. 'I refuse to go to visit the website' oh really!

The OS giken super lock LSD will be perfectly fine for 99.9% of applications straight out of the box.

Quote:

Originally Posted by Killerfish2012

We can take practicality out of the discussion if it's making you sweat. but as far as cost goes, you haven't explained what the major difference is between the Super Lock unit of OS Giken (the only one which we can even compare to wavetrac), and wavetrac, to justify the Large Price difference. I can't pay for the difference between a 1.5 way and 2 way diff because the difference is probably not even noticeable to 99% of the drivers that track their car.

I'm not interested in practicality and nor is the OP, and we are answering his questions, and this thread is for him, not you, trying to justify your purchase. It's up to him whether he wants to justify the extra costs. I'm just giving him facts.

Quote:

Originally Posted by Killerfish2012

exactly how many years have you spent driving at the track. I know I'm more experienced than you.

Hilarious, another ridiculous statement, how does this help the OP?

Quote:

Originally Posted by Killerfish2012

No, the OS giken is FAR less practical for anyone other than a professional race team to own. read what I wrote with care.

More Rubbish!

Quote:

Originally Posted by Killerfish2012

That's your opinion backed with claims of years of dealing with clutch style diffs, not experience behind the wheel, at a track, once the installs were complete.

Plenty of experience thanks.

Quote:

Originally Posted by Killerfish2012

It will "work", but it won't move the vehicle, appreciably.

Rubbish.

You seem to be making this thread all about you and your choice of Wavetrac, it's for the benefit of the OP, not you.

Quote:

Originally Posted by Killerfish2012

Lastly, here is video of a 335I at the track with the wavetrac fitted. Please tell me exactly how a superlock will improve his corner entry, exit, or any other aspect of his driving:

I get it, you talk rubbish about plated LSD's, which you most obviously know nothing about, apart from what you've seen in video and read on Google, so you try to steer this thread to your own agenda with ridiculous made up 'arguments' in your own head, to make you feel better about the purchase of a wavetrac.

We're not interested. The OP has privately PM'd me and told me he's going for the OS Giken, my work is done here.

Oh, and lastly, here is one of my sprint cars that I built from the ground up including making my own billet rear differential. Read it and you might learn something.

I get it, you talk rubbish about plated LSD's, which you most obviously know nothing about, apart from what you've seen in video and read on Google, so you try to steer this thread to your own agenda with ridiculous made up 'arguments' in your own head, to make you feel better about the purchase of a wavetrac.

We're not interested. The OP has privately PM'd me and told me he's going for the OS Giken, my work is done here.

Oh, and lastly, here is one of my sprint cars that I built from the ground up including making my own billet rear differential. Read it and you might learn something.

Hey good sales job man. The difference between you and me is that I own and track a 335I, not an evo. I ask for videos to back up your sales claims, and you give me a link to an evo site, with pictures of an engine build. So you're a mechanic? big deal, we're all dating supermodels here mate, its the internet for godsake.

I tracked my 335I for years, with an open diff, and was able to compensate for this disadvantage (read: traction control off, or partially disabled!). I modified my vehicle power out put levels to be about the same, as a stock E90M3, and I was 5-7 seconds faster than those vehicles at the track.

When it came time to fit a diff, I did my research, and went with the clear choice. OS giken, or drexler (Australia), are not very popular on here. Besides the LARGE price difference, there are several other issues with these types of diffs that made this a wavetrac or quaife forum.